Apparatus for projecting circular markings upon curved surfaces



May 7, 1957 J. A. USKERT 2,791,031

APPARATUS FOR PROJECTING 'CIRCULAR MARKINGS UPON CURVED SURFACES FiledApril 6, 1-954 2 Sheets-Sheet 1 UIIIIIIIIIIIII.flUI/IIIIIIAV/IIIIIIIIIIIIIIIII INI ENTOR.

J. A. USKERT 2,791,031

APPARATUS FOR PROJECTING CIRCULAR MARKINGS upon CURVED SURFACES May 7,1957 2 Sheets-Sheet 2 Filed April 6, 1954 United States Patent V IAPPARATUS FOR PROJECTING CIRCULAR MARKINGS UPON CURVE!) SURFACES JulieA. Uskert, Gary, Ind.

Application April 6, 1954, Serial No. 421,279

2 Claims. C1. 33-41) This invention relates to geometrical instrumentsand more particularly to a scriber for projecting circular markings uponcurved surfaces.

In the past whenever it was necessary to fit a pipe into a tank or intoanother pipe having curved or multiplanar surfaces, the projection ofthe circular pipe upon the curved work surface was made by trial orerror or by rough approximation. The result being that fittings were notexact and a great deal of time and effort were required.

Therefore, it is an object of this invention to provide an apparatus ofrelatively simple construction and capable of economical manufacturewhich is capable of projecting a circle of predetermined diameter upon acurved surface so that the pipe or other circular fitting to be insertedinto the opening out along the marl: made by the present apparatus willhave an exact fit with a minimum amount of effort and the elimination ofthe previous trial and error methods.

It is another object of this invention to provide an apparatus forscribing a projection of a circle upon a curved surface which may bereleasably attached to the curved work surface upon which the circularprojection is to be scribed, thus eliminating the need for any type ofpilot hole to be drilled through the curved surface as a guide for theapparatus and eliminating the requirement for fixedly securing theapparatus to the curved work surface as is necessary with previouslyknown instruments for this type of operation.

It is yet another object of this invention to provide a geometricalinstrument for scribing a projection of a circle upon curved surfaceswhich is capable of selective adjustment with respect to the angulardisposition of the apparatus with respect to the vertical center line ofthe curved work surface, or in the case of a pipe or tank, with respectto the transverse or diametric axis thereof.

Other objects and advantages will become apparent from a considerationof the following detailed description, forming the specification, andtaken in conjunction with the accompanying drawings, in which:

Figure 1 is a front elevational viewof the apparatus embodying thisinvention as applied to a curved work surface;

Figure 2 is a sectional view taken along line 2-2 of Figure 1;

Figure 3 is a vertical cross sectional view taken along line'3-3ofFigure 1;

Figure 4 is a sectional view taken along line 4- 4 of Figure 3 showingthe protractor at the top center of the curved work surface;

Figure 5 is a transverse cross sectional view taken on line 5-5 ofFigure 1;

Figure 6 is a cross sectional view taken on line 6=-6 of Figure 3; i

Figure 7 is a cross sectional view taken on line 7 7 of Figure 3; I

Figure 8 is a cross sectional view taken on line 8-8 of Figure 3;

Patented May 7, 1957 Figure 9 is a fragmentary cross sectional viewthrough a curved surface in which an opening has been cut in accordancewith the marking inscribed thereon by the apparatus of this inventionand showing a circular or cylindrical body received through the openingin the curved surface;

Figure 10 is a view similar to Figure 3 but showing only the lower endof the post and the protractor carried thereby with the post at apredetermined angle with respect to the perpendicular center linethrough the top center of the curved work surface; and

Figure 11 is a fragmentary view in cross section showing a modified formof the attaching means for the apparatus.

With continued reference to the drawings, there is shown a geometricalinstrument, generally indicated at 10, which is an apparatus forscribing circular projections upon curved surfaces, The apparatus 10includes in its construction an upstanding post 12 having its lower endtapered as at 14 which defines a point adapted to engage-in a punch markmade in a curved Work surface '16 to indicate the desired center of anopening to be made throughthe work surface for receiving a circular bodytherein. The work surface 16 may be the curved w'allof a tank or pipeinto which another pipe or circular body is to be fitted.

A scale arm guide, generally indicated at 18, iscarried by the post 12for sliding movement longitudinally thereofintermediate its ends. Theguide 18 includes a sleeve 20 which is freely slidable longitudinally ofthe post 12 and carries'intermediate its ends a hollow cylindrical tubeor pipe 22 which extends with its longitudinal axis normal to thelongitudinal axis of the sleeve 20, hence the axis of the tube is alsonormal to the axis of the ost 1 2. A scale arm 24 in the form of atubular rod having inscribed thereon units of lineal measure 26 andslidably'carried by the tube 22 in the bore therethrough for movement in'a rectilinear path through the guide 18 perpendicular to the post 12.Lock means in the form of a wing bolt 28 is carried by the tube or pipe22 adjacent one end thereof in a suitably threaded opening therethroughcommunicating with the central bore of the tube whereby the scale arm,defining, a beam, may be selectively secured in its rectilinear path ofmovement through the :guide 18 and specifically through the tube or pipe22thereof.

A collar 30 is slidably mounted on the .post 12 and disposed between theguide 18 and the pointed end 14 of the post,- and collar 30 carries lockmeans in the form of a wing bolt or nut 32 whereby the collar can besecured in any desired position along the length of the rod 1 2 betweenthe pointed end 14 and the guide 18. The collar 30 acts as astop meansto limit the downward movement of the scale arm guide 18 on the post 12,and the stop collar 30 is adjustable longitudinally of the post 12 sothat the position of the guide lfirnay be selectively predeterminedalong the longitudinal extent of the post 12.

With the tapered or pointed end 14 of the post 12 in engagementwith thepunch mark 15 in the work surface 16, the inst inent or apparatus 10 isprovided with attachin'g'meansror releasabl'y securing it on the curvedwork surface 16. This attaching means comprises a'plurality of arms 34,36 and 38, each of which carries at one 'end a magnet 40 which ispivotally attached to the adjacent end 'of the respective arm. The otherend of the arm 34 remote from the end upon which a magnet '40 is'pivotally connected, is pivotally secured between 30. The collar 46 maybe fixed in a stationary position 1 upon the post 12 by a wing bolt ornut 48 carried therer by, which when tight willengage the post 12 tosecure the collar 46 in a fixed position longitudinally of the'post.

Another collar 50,,somewhate similar to the collar 46, has formedthereon angularly spaced pairs of spaced, parallel, laterally projectingears 52 and 54 to receive therebetween the ends of the arms 36 and 38respectively. A rivet 56 passes through transversely aligned openings inthe ears 52 and an aligned or registering opening in the arm 36 adjacentthe end thereof remote from the magnet 40 so as to pivotally secure theend of the arm to the collar 50. Similarly, a rivet 58 is receivedthrough transversely aligned openings in the ears 54 and through aregistering opening in the arm 38 adjacent its end remote from the endwhich pivotally carries the magnet 40 so that the arm 38 is pivotallyconnected to the collar 50 and extends laterally therefrom, in similarmanner to the manner in which the arms 34 and 36 also laterally projectfrom their respective collars. This structure is clearly shown in Figure8.

Thus, by properly adjusting the collars 46 and 50, the collar-50 beingslidably mounted on the post 12 and adapted to be secured therealong ina fixed position by a Wing bolt 60, and the arms 34, 36 and 38 extendedoutwardly and downwardly therefrom so that the magnets carried at theends of the respective arms contact the curved surface 16,willreleasably secure the apparatus thereon, assuming that the material ofthe curved work surface 16 is of the magnetic type.

If, however, the work surface 16 is of a non-magnetic material, then avacuum cup, such as the vacuum cup 62 as shown in Figure 11, may replacein the holder 41 which is pivotally secured to the ends of therespective arms remote from the collars 46 and 50 respectively. Thevacuum cup 62 may be secured in the respective holders 41 by a screw 64in the manner shown in Fig ure 11.

It will be noted that the collar 50 carrying the arms 36 and 38 isdisposed between the collar 46 on the post 12 and the pointed or taperedend 14 of the post.

One end 66 of the scale arm 24 carries a guide sleeve 68thereon. Theguide sleeve 68 is secured to the end 66 ofthe scale arm 24 as by beingriveted thereto centrally intermediate its ends and has its axisdisposed normally to the longitudinal axis of the arm 24. A scriber 70is received in the bore 72 of the guide sleeve 68 and is freely movabletherethrough in a rectilinear'path parallel to the post 12 but spacedtherefrom.

The upper end of the scriber 70 is provided with an enlarged circularhead 74 of greater diameter than the bore 72 so that the scriber 70cannot pass entirely through the guide sleeve 68, and in additionprovides additional weight to urge the scriber downwardly through thebore 72 of the guide sleeve 68 toward the, curved surface of the workpiece 16. The lower end, or end remote from the head 74, carries thereona hollow cylindrical holder 76 having springs 78 disposed within thebore thereof and extending longitudinally of the bore so as toresiliently grip a marking instrument 80 therein, the pointed end of themarking instrument, which may be a pencil or soap stone or other meanswhereby a mark may be inscribed upon the surface 16, projects outwardlyfrom the end of the holder 76 remote from the end thereof secured to thescriber 70.

Thus, the scriber 70 is carried by the scale arm 24 in spaced relationto the post 12 and is movable with the arm as the arm is moved in acircular path perpendicular to the post. The movement of the arm 24 inthe circular path normal to the post 12 is possible since the sleeve 20is freely rotatable about the post 12 and rests upon the adjacent-faceof the stop collar 30 which defines a bearjug surface. a

Therefore, to scribe a circular projection upon the curved work surface16, a punch mark is made in the work surface 16 to indicate the centerof the circular projection to be scribed thereon and the pointed ortapered end is engaged in the punch mark 15. In order to insure that thepost 12 is in proper vertical alignment with the vertical center linethrough the punch mark 15, and hence the center of the circularprojection to b inscribed upon the curved surface 16, the post 12 is adjusted until the bubble in the bubble type level 82 carried on the tube22 is centered therein. With the post 12 properly oriented in a verticalposition as indicated by the level 82, the arms 34, 36 and 38 are thendisposed so that the magnet 40 in the case where the material of thework piece is magnet, or the vacuum cups 62 in the case where thematerial of the work piece is non-magnetic, contact the outer surface ofthe Work piece to releasably secure the apparatus 10 thereon. It will beappreciated that the collars 50 and 46 may be suitably adjustedlongitudinally of the post 12 so as to have the arms extend therefrom insuch manner as to afford the best attaching contact with the surface ofthe work piece 16. The nut 28 may then be loosened as to permit thescale arm or beam 24 to be moved through the scale arm guide 18 in arectilinear path perpendicular to the post 12 and thereby move thescriber 70 carried by the arm or beam 24 to a predetermined distance inspaced relation to the post 12. The scale defined by the units ofmeasure 26 on the arm 24 will indicate the distance between the centerlines of the post 12 and scriber 70. In order to aid in determiningquickly and accurately the distance between the scriber and the post, arectangular opening 84 is provided through the side wall of the tube 22centrally intermediate its ends and generally along the longitudinalaxis of the post 12, to define a window through which the different onesof the units of measure 26 may be visually perceived. Thus, the distancemay be readily and accurately determined between the scriber 70 and thepost 12, and then the set screw or wing bolt 28 tightened to fix theselected distance between the scriber and the post. The arm or beam 24is then moved in its circular path and the scriber 70 is moved therewiththereby causing the point of the marking instrument to mark or inscribethe projection of the circular path of predetermined diameter upon thecurved surface of the work piece 16. With the marking inscribed on thework piece, the apparatus 10 is removed from the Work piece, and thework piece is cut along the inscribed mark to define a generallyelliptical opening 86 therethrough to receive therein with a tight fit acircular pipe or other circular body 88, as shown in Figure 9.

Where the opening through the curved work piece 16 is to be cut at anangle with respect to the vertical center line through the top center ofthe curved work piece, the

protractor 90 is set along the vertical center line through the topcenter of the worker pipe or tank through which the opening is to becut, with the center line coincident with the vertical or ninety degreereading on the protractor scale 91. The protractor 90 is operativelyconnected to the post 12 of the apparatus 10 by a collar ,92 slidablymounted on the post 12 adjacent its lower or pointed end 14 and fixedlysecurable thereon by means of a wing-headed set screw 94. The collar 92has formed thereon a threaded shaft 96 which projects outwardlytherefrom perpendicular to the axis of the bore of the collar and in adirection away from the direction in which the set screw 94 extends, orto the side of the collar opposite to the side which carries the setscrew 94. The shaft 96 extends transversely through an arcuate slot 98formed in the body of the protractor 90 and concentric with the scale91, and a nut 100 is threadedly received on the end of the shaft 96projecting through the slot 98 so that the protractor 90 will be broughtin face to face engagement with the collar, defining a sliding clamp forthe protractor, so that the protractor is frictionally engaged againstthe adjacent face of the collar and restrained from movement. However,it will be apparent, that by loosening the nut 100, the post 12 may beinclined either to the right or to the left of the vertical center linethrough the top center of the work piece 16, as viewed in Figures 3 and4 and Figure 10, and secured at any desired angular disposition asindicated on the scale 91 by again tightening the nut 100. The scribingoperation will then proceed in the manner hereinbefore described withthe scriber 70 set at a predetermined distance from the post 12 so as toproject a circle of predetermined diameter upon the curved surface ofthe work piece 16.

It will be apparent that, with the apparatus inclined from its verticalposition, the attachment means whereby the apparatus may be releasablysecured upon the Work piece 16, will be appropriately adjustedlongitudinally of the post 12, as well as the stop collar 30 and scalearm guide 18 being suitably adjusted longitudinally of the post 12 inorder to facilitate the subsequent scribing operation.

It is pointed out, that as the scriber 70 is moved in a circular pathabout the longitudinal axis of the post 12 as the axis of rotation, tothe broken line position shown in Figure 2, the apparatus or instrumentIt) will be maintained in its proper, pre-selected angular relation tothe curved surface of the work piece 16 by the attaching means carriedby the post 12 and which are adjustable longitudinally thereof.

From the foregoing, it will be apparent that there has been provided anapparatus for scribing circular projections upon curved surfaces, whichcomprises an upstanding post having its lower end engaging a curvedsurface upon which the projection of a circle is to be scribed, an armguide 18 carried by the post 12 intermediate its ends for movement in acircular path perpendicular to the post, an arm carried by the guide formovement in a rcctilinear path which lies perpendicular to the post 12,attaching means carried by the post for selective adjustmentlongitudinally thereof to releasably secure the post upon the curvedsurface, and a scriber carried by the arm 24 in spaced relation to thepost 12 and movable along with the arm 24 and guide 18 in its circularpath to mark the projection of a circle upon the curved surface. Hence,it will be seen that the scriber 70 is carried by the post 12 formovement in a circular path about the post as an axis.

While there are shown and described the preferred embodiment of theinvention, it is to be understood that the structure is susceptible tochange and modification within the practicability of the invention andtherefore should be limited only by the scope of the claims appendedhereto.

What is claimed is:

1. An apparatus for scribing circular projections upon curved surfaces,comprising an upstanding post having its lower end engaging a curvedsurface upon which the projection of a circle is to be scribed, an armguide carried by said post intermediate its ends for movement in acircular path perpendicular to said post, an arm carried by said guidefor movement in a rectilinear path which lies perpendicular to saidpost, attaching means carried by said post for selective adjustmentlongitudinally thereof to releasably secure said post upon the curvedsurface, and a scriber carried by said arm in spaced relation to saidpost and movable with said arm in its circular path to mark theprojection of a circle upon the curved surface, said attaching meanscomprising a first collar, an arm pivotally connected at one end to saidfirst collar and pivotally carrying at its other end means detachablysecurable upon the curved surface, a second collar, a pair of angularlyspaced arms, each of said pair of arms being pivotally connected at oneend to said second collar and means detachably securable upon the curvedsurface pivotally carried at the other end of each of said pair of arms.

2. An apparatus for scribing circular projections upon curved surfaces,comprising a post having one end in engagement with a curved surfaceupon which the projection of a circle is to be scribed, a scribercarried by said post in spaced relation thereto for movement in acircular path about said post as an axis, said scriber also mounted formovement in a rectilinear path parallel to said post, and attachingmeans carried by said post for selective adjustment longitudinally ofsaid post and detachably securing the post upon the curved surface, saidscriber marking the projection of a circle upon the curved surface as itis moved in its circular path, said attaching means comprising a firstcollar, an arm pivotally connected at one end to said first collar andpivotally carrying at its other end means detachably securable upon thecurved surface, a second collar, and a pair of angularly spaced arms,each of said pair of arms being pivotally connected at one end to saidsecond collar and means detachably securable upon the curved surfacepivotally carried at the other end of each of said pair of arms.

References Cited in the file of this patent UNITED STATES PATENTS988,188 Graham Mar. 28, 1911 994,665 Weimer June 6, 1911 2,497,853Arnold et al. Feb. 21, 1950 2,594,457 Kunzler Apr. 29, 1952 2,612,695Schneider Oct. 7, 1952 2,659,972 Norris Nov. 24, 1953 FOREIGN PATENTS511,875 Germany Aug. 22, 1931 OTHER REFERENCES Goddard: PeculiarCurved-Surface Intersections Scribed Easily, American Machinistmagazine, September 12, 1946, page 144.

